Martin H. Rathke, (born Aug. 25, 1793, Danzig, Prussia [now Gdańsk, Pol.]—died Sept. 3, 1860, Königsberg [now Kaliningrad, Russia]) German anatomist who first described the gill slits and gill arches in the embryos of mammals and birds. He also first described in 1839 the embryonic structure, now known as Rathke’s pouch, from which the anterior lobe of the pituitary gland develops.

Rathke ended a 10-year medical practice in his hometown when he became professor of physiology at the University of Dorpat and, later (1835), professor of zoology and anatomy in Königsberg. An outstanding embryologist, Rathke thought the gill arches were vestiges of ancestral gills, but he also recognized their significance in the later development of the associated blood vessels. Rathke also did pioneering research in marine zoology. He was elected a fellow of the Royal Society in 1855.